Heat indicator for internal-combustion engines



Oct. 8, 1929. J. ZUBATY 1,731,207

HEAT INDICATOR FOR INTERNAL ,COMBUSTION ENGINES Filed March 12, 1927 gwumtoz ym z/ 2225/ cri Patented Oct. 8, 1929 1 UNITED STATES PATENT OFFlCE JOSEPH ZUBATY, OF FLINT, MICHIGAN, ASSIGNGR TO A C SPARK PLUG COMPANY, OF

FLINT MICHIGAN, A COMPANY OF MICHIGAN HEAT INDICATOR FOR INTERNAL-COMBUSTION ENGINES Application filed. March 12, 1927. Serial No. 174,819.

This invention relates to heat indicators as applied to internal combustion engines and particularly to engines used on automotive vehicles.

In carrying out my invention I make use of a surface having a painted substance which has the well known property of changing its color when a degree of heat above a certain temperature is applied thereto.

In the embodiment as illustrated a solid metal rod is attached to the radiator opening or cap, the lower end of the rod extending into the air space above the water in the radiator, while at the upper exposed end I secure a metallic screen. The screen end has applied thereto on the side facing the driver a coating of heat sensitive paint and a glasscnclosure may be placed on both sides of the screen for protective purposes. The heat from the air space over the radiator is communicated by the rod to the painted surface on the screen and when the temperature attains a certain degree the color of the paint will change thereby notifying the driver that the danger point has been reached. The advantage of the screen is that it presents an irregular surface and thereby improves the visibility of the color change in that the light rays will be reflected from a rounded instead of a flat surface. The screen further affords a large radiating surface so that when heat is transmitted from the rod to the screen only that portion of the paint near the rod will change radically the 7 part furthest away not changing at all while the intermediary portion is a gradation of colors. 7 7

My metal conducting rod has a heat insulat- 7 ing bushing placed along the line of its contact with the radiator cap. and the retaining ring for the screen, the purpose of which is to prevent a radiation of heat before it reaches the painted surface.

My invention is disclosed in the accompanying drawing which Figure 1 is a transverse section through a radiator cap looking from the rear.

Figure 2 is a section on line 2-2 of Figure 1.

Figure 3 is a View similar to Figure 2 of a modified form.

Figure 4 is an enlarged view of my screen with the heat sensitive paint applied thereto.

Referring to Figure 1, 1 indicates the radiator shell, 2 the upper tank of the radiator having an outturned annular flange 3 over which is secured a threaded collar 4'for the reception of the radiator cap 5. The radia tor cap has an opening 6 at its upper portion and through this opening there extends a threaded end 7 of a holder 8 to which a screen 17 is secured. This screen holder has a shoulder 9 resting on the radiator cap and is held in place by means of a washer 10 and a nut 11 threaded on the end 7 interiorly of the radiator cap.

The ring has a ing bushing 13 in which is received the solid metal rod 14, preferably of copper, although I may use a hollow tube as well. The lower end 15 of the rod projects into the air space of the upper tank 2 but may extend down into the water while the upper end at 16 is molecularly or integrally secured to the screen 17 such as by welding or soldering; This screen is also secured at its periphery to the ring 8 and has applied thereto a coating of heat sensitive paint 18 and from the inspection of Figure 4 it will be apparent that due to the irregularie ties in the screen surface the surface of the paint will likewise be irregular and cause a diffusion inthe rays of light falling thereupon as shown at 00. This diffusion will make the bore 12 with a heat insulat-- change in color of the heat sensitive paint more obvious and if but a thin coating is applied the screen and paint will be translucent, or substantially transparent.

Because of the irregularity of the surface of the screen, it will be apparent that a greater degree of visibility will be obtained; that is, the light rays will be reflected from a rounded instead of a flat surface, giving a greater area of illumination. This is particularly advantageous during night driving against the glaring head lights of an approaching vehicle, or against sunset, or when other conditions obtain which make the oncoming light rays substantially horizontal. When such conditions prevail the paint on the rounded section of the wires will be visible regardless of the direction of the light rays.

a danger point.

It is to be further noted that the screen 17 is attached only at its lower portion to the rod 14 from which it is evident that the heat is first communicated to the screen at its place of attaclnnent. The screen affords a relatively large radiating surface so that the upper portion thereof rarely has sufficient heat communicated to it to cause the paint thereon to change color while the lower portion changes color immediately sufiicient heat reaches the upper end of rod 14. The intermediate portion of the painted surface forms a gradation of colors between the two extremes. The extent to which the color change rises toward the upper portion of the screen determines the thermostatic condition of the water in the radiator.

By referring to Figure 3 it will be seen that I provide the ring 8 with annular receses 19 for the reception of windows 20 the purpose of which is to protect the painted surface.

The operation of my device is as follows: The heat from the vapor of the Water in the tank 2 will be conducted by the rod 1 f from its lower end 15 to its upper end 16 and from the end 16 to the metallic screen 17, integrally united therewith. W hen the quantity of heat so transmitted reaches a suiliciently high degree it will cause the normal color, for instance yellow, of the heat sensitive paint surface at the upper end of the rod 1 to change to a different color, for example red, the area of the change depending on the degree of heat, thereby notifying the driver when the temperature within the radiator has reached the As the temperature recedes the color change will reverse.

Obviously, the rod 15 may extend down below the normal level of the water in the radiator.

I claim:

1. In an automotive vehicle, a heat indicator, comprising a rod applied to the radiator, the lower end of said rod being disposed within and the upper end without the radiator, a screen on the outer end of said rod, and a coating of heat sensitive paint on said screen.

2. The combination of claim 1, and a holder secured to the radiator cap, said holder having an upper circular portion, said screen secured to said circular portion.

8. A heat indicator for automobiles, a rod projecting into the air space of the radiator, one end of the rod extending through the radiator cap, a holder at the exposed end, a screen secured in said holder and attached to said rod, and means on said screen to indicate temperature differences.

i. In combination with an automotive vehicle having a radiator, a cap on said radiator having an opening, a means for indicating temperature differencescomprising a holding member mounted in said openin a heat insulating bushing mounted in said holding memher, a heat conducting element mounted in said bushing and extending beyond both ends thereof, and a metallic member mounted in said holding'member and secured to said ele ment, and means on said metallic member for giving visible indication of temperature forming to the irregular surface for diffusing light and for indicating temperature differences.

8. ln aheat indicator for application to a container the thermal condition of the fluid contents of which is to be determined, a conducting element extending into the container, a member in heat conducting relation with said element, and a coating of uniform color having an irregular light reflecting and diffusing surface on saidv element, said coating adapted to assume a gradation of colors with increased temperature in the fluid.

9. In a heat indicator for application to a container the thermal condition of the fluid contents of which is to be determined, a conducting element extending into the container, a member in heat conducting relation with said element, and a coating of a uniform color having an irregular light reflecting surface on said element, the portion of said coating farthest away from said element remaining substantially unchanged and the portion nearest the element showing the initial change with variations in temperature of the fluid.

10. In a heat indicator, a fluid container to which said indicator is applied, a heat con-V ducting element extending into container, a metallic screen in heat conducting relation with said element, said screen having an irregular surface and positioned outside the container, and a coating of heat sensitive paint on said screen and conforming to the irregular surface for diffusing light and for indicating temperature differences.

11. In a heat indicator for the radiator ofv an automotive vehicle, a heat conducting ele ment extending into the radiator, a heat conducting member rigidly and directly secured to said element, and a heat sensitive coating of a single uniform color on said'element,said coating adapted to assume a gradation of colors with increases intemperature.

12. In a heat indicator for the radiator of an automotive vehicle, a heat conducting element extending into the radiator, a heat conducting member rigidly and directly secured to said element, and a heat sensitive coating of a single uniform coloron said element, said. coating adapted to assume a gradation of colors with increases in temperature, the up per portion of said coating remaining unchanged at all times and the lower portion showing the initial color change.

In testimony whereof I afiix my signature.

JOSEPH ZUBATY. 

